1. Field of the Invention
The present invention relates to an automatic original feed unit for copying machines and, more particularly, to an original pay-off device for use in paying off one by one the originals on an original supplying pay toward a copying position.
2. Description of the Prior Art
An automatic original feed unit is capable of automatically feeding one by one originals to be copied, which are stacked on a supplying tray or feeding table, toward a copying position through an operation of a copying button, and automatically discharging originals, which have been copied, onto a receiving tray.
FIG. 1 is a schematic illustration of an automatic original feed unit. Though this construction shows an embodiment of an automatic original feed unit be capable of applying an original pay-off device, for the convenience of description it is used as a prior art, since the construction itself does not relate to this invention, directly, and similar to that of conventional unit.
Referring to FIG. 1, a copying machine 1 is provided with an automatic original feed unit 2 which is integrally formed with a copy board thereof. This original feed unit 2 consists of a main body 3, and a movable body 5 pivotally supported on a shaft 4 in the main body 3 such that the movable body 5 can be moved in the vertical direction on the copy board. The main body 3 is provided with an original supplying tray 7 onto which one or a plurality of originals are inserted from a chute 6, a pay-off roller 8 driven by an original feeding command or instruction to pay off an original from the supplying tray 7, and a feeding roller 9 driven in the same manner at the same peripheral speed as the pay-off roller or supplying roller 8 to transfer the original towards the side of movable body 5.
The movable body 5 is provided with a transfer device consisting of a conveyor belt 11, pulleys 12, 13, idlers 14, 15, 16, a guide roller 17 and a discharge roller 18, so as to transfer an original which has been fed from the feeding roller 9 and which is placed on the copy board 10 made of glass to a proper position, and discharge the original on the copy board 10 at the completion of a copying operation therefor.
The pulley 12 (or 13) is driven by a motor (not shown) directly or via an electromagnetic clutch when an original is fed or when an original is discharged.
The movable body 5 is provided in addition to the above-mentioned members with a stopper 19 which is projected on the surface of and at the front side of the copy board 10 by a plunger action so as to stop the original to a proper position during the transfer thereof.
Reference numeral 20 denotes a guide member adapted to guide the original from the guide roller 17 to the discharge roller 18 during an original discharging operation, 21 a discharge port, and 22 a receiving tray serving also as a cover for the movable body 5.
In such a conventional automatic original feed unit, it costs much labor to introduce an original onto an original supplying tray 7 and allow the front end of the original to accurately contact a pay-off rollers. This spoils the advantages of a copying machine having an automatic original feed unit, and often prevents originals from being accurately payed off one by one. As a result, copying errors or the jamming of originals occurs frequently.